The present invention relates to polymer alloys for use as dimensional support elements for shoes and specifically to an alloy of incompatible ionomeric and nonionic polymers which is both stiff and moldable.
In footwear and other clothing item applications, the use of inherently stiff polymer films as stiffener support elements is desirable from the standpoint of durability and dimensional support but such stiff polymers are generally difficult to adhere to a shoe substrate and mold under reasonably low temperatures and pressures to the shape of the portion of the shoe, e.g. heel, toe, arch, (or other clothing item) into which the polymer stiffener is to be incorporated.
Alloys of polymers are possible in such applications but necessarily comprise alloys of compatible polymers having essentially the same chemical and physical characteristics. Although it is possible to alloy compatible polymers in bulk or sheet form to a degree sufficient to avoid layering and/or precipitation of the individual polymers in the alloy mixture, incompatible polymers, e.g., ionic and non-ionic, such as cross-linked ionomers and non-ionic polymers such as hydrocarbons--do not alloy well generally, and specifically will not alloy well enough to allow construction of a film or sheet suitable for use as a shoe or other clothing item stiffener. If layering occurs within a polymer alloy, any film constructed thereof loses homogeneity, fails to exhibit the properties of a true alloy, and rather exhibits awkward physical characteristics of its individual components as if fused in globular form.
It is, therefore, an object of the invention to provide a true alloy of incompatible polymers.
It is a further object of the invention to provide an alloy of incompatible polymers formable into a film for application as a stiffener in footwear or other clothing.